90/6.8 Angulon Rear Element

[IanG]

My 1950's model is very soft in the last 1/4" or so in the corners of 4x5 at f16-f22. The 1930's chart indicates about 200mm image circle at f22 and 105 degrees of coverage so I'm not so sure they are the same design.

More recent Schneider data:http://www.schneideroptics.com/info/.../6,8-90mm.html indicates only 154mm of coverage at f16, 81 degrees and 90x120mm recommended format, so not quite enough coverage for 4x5 unless you are exactly centered with no tilts or shifts.

90mm is normally a little wide for my compositions, so I do alright by cropping a little bit.

Jon
Attachment 111447

Dean Jones posted here a few years ago that there was a variation in the cell spacing caused by the Compur shutters and that if the spacing was too great then the lenses tended to be softer at the corners. He said that he had corrected the spacing on some Angulons and that improved the performance significantly.

I've had 3 90mm f6.8 Angulons and the first two were por performers, the third is excellent and at f16 - f22 and is part of migh light weight kit I use in Turkey, often hand held.

Those old Schneider specifications only list the German formats like 9x12, so even lenses designed to cover 10"x8" are listed as covering 18x24 the European standard.

Ian

[mdarnton]

Pictures like this one remind me that one man's 105 degrees might be another's 90 degrees: http://www.shorpy.com/node/17073?size=_original#caption Check the detail at the top of the photo--this is seen quite often in photos from the early part of the 1900s, and it happens often enough that it makes me think that it probably didn't bother the photographers at all--I guess they were just happy to have the coverage, and the result in the prints most likely looked fine to them, too. Now we expect everything to be perfect at 100% on a computer screen, not in a contact print at a normal viewing distance.

[BetterSense]

Good point. When I attended a photography exhibition at the Amon Carter museum a few years ago, I was struck by just how popular medium-format contact prints were. You don't see images that small much among photography practitioners now...I suppose it was the era's version of "web resolution"...cheap and good enough to get a picture. And certainly easy on lens requirementst.

I have two 90/6.8 angulons but can't say I have tested them hard. One is on a fixed-focus 4x5 which I used for polaroids a lot. I would like to get a 90mm lens of this size for use on 2x3 film, that was good enough for general landscape use with enlargements. The super angulon-type lenses are overly big and expensive for the little 2x3 camera I plan to build.

[Carsten Wolff]

Check what Ole Tjurgen has done with this lens in 4x5 and 5x7 (!); let us know how it worked out for you and whether you scored the rear cell off Guilherme.
I used one on 4x5" as a (convertible) hiking lens and it was a decent performer.

[IanG]

Check what Ole Tjurgen has done with this lens in 4x5 and 5x7 (!); let us know how it worked out for you and whether you scored the rear cell off Guilherme.
I used one on 4x5" as a (convertible) hiking lens and it was a decent performer.

Ole's lens is the older 90mm f6.8 Angulon which has much greater coverage.

Ian

[Bob Sawin]

Upon closer inspection I can see the recessed rear element. When I get a chance I'll take it out and se if I like it or not. Thanks for the great info.

[Michael E]

Dean Jones posted here a few years ago that there was a variation in the cell spacing caused by the Compur shutters and that if the spacing was too great then the lenses tended to be softer at the corners.

Check the rear thread of the shutter: If it extends all to way to the end of the barrel, the spacing is too wide. The rear element has kind of a collar, so the thread has to be recessed about 2 mm.